How to add new povray elements to vapory?

[tanuva]

tl;dr: How does the syntax used in the class documentation comments that specify a POVRayElement's content work?

I'm trying to make heightfields available in vapory. From the existing POVRayElements, I deduce the syntax should be something like """ 'parameter_name', default_value_implying_type, 'parameter2_name', another_default """.

• How about string parameters?

• How does that work for something like ImageMap which doesn't have a named parameter? If I extend ImageMap like this: """ ImageMap('image', 'my_image.png') """ (before adding additional image_map parameters), Python throws the following at me:

  Traceback (most recent call last):
  File "scene.py", line 36, in <module>
  VideoClip(make_frame, duration = 2).write_gif("anim.gif",fps = 20)
  File "/Library/Python/2.7/site-packages/moviepy/video/VideoClip.py", line 106, in __init__
  self.size = self.get_frame(0).shape[:2][::-1]
  File "<decorator-gen-14>", line 2, in get_frame
  File "/Library/Python/2.7/site-packages/moviepy/decorators.py", line 89, in wrapper
  return f(*new_a, **new_kw)
  File "/Library/Python/2.7/site-packages/moviepy/Clip.py", line 95, in get_frame
  return self.make_frame(t)
  File "scene.py", line 31, in make_frame
  return scene(t).render(width = 300, height = 200,
  File "scene.py", line 14, in scene
  ImageMap(image = "map.png"),
  TypeError: __init__() got an unexpected keyword argument 'image'

This is vapory 0.1.1 from pip on Python 2.7.

[Zulko]

please provide the whole code (in particular the implementation of imagemap)

[tanuva]

I'm sorry, should've added that right away. The whole implementation is this (actual code wasn't changed):

class ImageMap(POVRayElement):
    """ ImageMap('image', 'my_image.png') """
    povray_name= 'image_map'
    url = wikiref+'Image_Map'

The code using it is this (excerpt):

sphere1 = Sphere([-4, 2, 2], 2.0,
        ImageMap(image = "map.png"))

(Not sure if that would even result in correct pov syntax, but I'd expect vapory to write at least a pov file I can check manually.)

I actually only changed the class comment but don't really understand how it is parsed. Reading vapory's readme again (RTFM, future self!), I understand that those comments are not parsed by some magic but simple usage instructions. I see now how POVRayElement works, but I don't get how ImageMap breaks here as the default implementation of POVRayElement works the same way f.e. for Camera.